Physical layer routing and monitoring

Abstract

Systems and methods for allocating optical circuits on optical mesh networks are disclosed herein. For example, the disclosed methods include identifying a new circuit to be added to a mesh optical network and identifying a set of potential paths for the new circuit. For each optical link in each identified potential path, costs are determined for a plurality of frequency slots of allocating the new circuit to a potential path including the optical link. The cost of allocating a given frequency slot on a given optical link is determined in part based on the lengths of optical circuits that can traverse the given optical link using that frequency slot. Total cost values are calculated for allocating available frequency slots over each of the identified potential paths, and one of the identified potential paths and one or more of the available frequency slots are allocated for the new circuit.

What is claimed is: 
     
       1. A computer-implemented method, comprising:
 identifying a new circuit to be added to a mesh optical network having a plurality of optical links, each optical circuit including a source node and a destination node between which an optical signal carried over the optical circuit is not converted to an electrical signal; 
 identifying a set of potential paths for the new circuit through the mesh optical network; 
 for each optical link in each identified potential path, determining respective costs for a plurality of frequency slots of allocating the new circuit to a potential path including the optical link, wherein the cost of allocating a given frequency slot on a given optical link is determined in part based on the lengths of optical circuits that can traverse the given optical link using that frequency slot; 
 calculating total cost values for allocating available frequency slots over each of the identified potential paths for the new circuit based on the costs determined for the frequency slots for each optical link along the potential paths; 
 selecting one of the identified potential paths and one or more of the available frequency slots for the new circuit based on the calculated total cost values; and 
 communicating routing and spectrum allocation instructions based on the selected path and the selected one or more frequency slots to a plurality of nodes in the network to implement the new circuit. 
 
     
     
       2. The method of  claim 1 , wherein selecting one or more of the available frequency slots for the new circuit comprises selecting a plurality of adjacent frequency slots. 
     
     
       3. The method of  claim 1 , wherein selecting one of the potential paths and the one or more frequency slots includes selecting the one or more frequency slot over the potential paths that have the lowest calculated total cost value. 
     
     
       4. The method of  claim 1 , further comprising assigning a higher cost to frequency slots that are available for longer optical circuits and a lower cost to frequency slots that are only available for shorter optical circuits. 
     
     
       5. The method of  claim 1 , wherein the cost of allocating one frequency slot over a given optical link to a new circuit differs from the cost of allocating a different frequency slot over the given optical to the new circuit based on the locations of the frequency slots in the electromagnetic spectrum. 
     
     
       6. The method of  claim 1 , comprising, after selecting one of the identified potential paths and one or more of the available frequency slots for the new circuit based on the calculated total cost values, calculating updated costs for frequency slots over a plurality of optical links in the optical mesh network based on the selection. 
     
     
       7. The method of  claim 6 , wherein the updated costs are calculated only for links included in the selected identified potential paths. 
     
     
       8. The method of  claim 1 , wherein identifying a set of potential paths further comprises identifying a subset of paths having a path length within a configured percentage of a smallest path length identified between the source node and the destination node, wherein path length is measured in terms of total optical fiber length along the respective paths. 
     
     
       9. A non-transitory computer-readable medium storing instructions that, when executed by one or more processors, cause the one or more processors to:
 identify a new circuit to be added to a mesh optical network having a plurality of optical links, each optical circuit including a source node and a destination node between which an optical signal carried over the optical circuit is not converted to an electrical signal; 
 identify a set of potential paths for the new circuit through the mesh optical network; 
 for each optical link in each identified potential path, determine respective costs for a plurality of frequency slots of allocating the new circuit to a potential path including the optical link, wherein the cost of allocating a given frequency slot on a given optical link is determined in part based on the lengths of optical circuits that can traverse the given optical link using that frequency slot; 
 calculate total cost values for allocating available frequency slots over each of the identified potential paths for the new circuit based on the costs determined for the frequency slots for each optical link along the potential paths; 
 select one of the identified potential paths and one or more of the available frequency slots for the new circuit based on the calculated total cost values; and 
 communicate routing and spectrum allocation instructions based on the selected path and the selected one or more frequency slots to a plurality of nodes in the network to implement the new circuit. 
 
     
     
       10. The computer-readable medium of  claim 9 , wherein selecting one or more of the available frequency slots for the new circuit comprises selecting a plurality of adjacent frequency slots. 
     
     
       11. The computer-readable medium of  claim 9 , wherein selecting one of the potential paths and the one or more frequency slots includes selecting the one or more frequency slot over the potential paths that have the lowest calculated total cost value. 
     
     
       12. The computer-readable medium of  claim 9 , wherein the one or more processors assign a higher cost to frequency slots that are available for longer optical circuits and a lower cost to frequency slots that are only available for shorter optical circuits. 
     
     
       13. The computer-readable medium of  claim 9 , wherein the cost of allocating one frequency slot over a given optical link to a new circuit differs from the cost of allocating a different frequency slot over the given optical to the new circuit based on the locations of the frequency slots in the electromagnetic spectrum. 
     
     
       14. The computer-readable medium of  claim 9 , storing instructions that, when executed by the one or more processors, cause the one or more processors to, after selecting one of the identified potential paths and one or more of the available frequency slots for the new circuit based on the calculated total cost values, calculate updated costs for frequency slots over a plurality of optical links in the optical mesh network based on the selection. 
     
     
       15. The computer-readable medium of  claim 14 , wherein the updated costs are calculated only for links included in the selected identified potential paths. 
     
     
       16. A system comprising:
 an optical mesh network including a plurality of nodes interconnected by optical links; 
 a memory for storing a representation of the optical mesh network; and 
 a processor configured to: 
 identify a new circuit to be added to a mesh optical network having a plurality of optical links, each optical circuit including a source node and a destination node between which an optical signal carried over the optical circuit is not converted to an electrical signal; 
 identify a set of potential paths for the new circuit through the mesh optical network based on the stored representation; 
 for each optical link in each identified potential path, determine respective costs for a plurality of frequency slots of allocating the new circuit to a potential path including the optical link, wherein the cost of allocating a given frequency slot on a given optical link is determined in part based on the lengths of optical circuits that can traverse the given optical link using that frequency slot; 
 calculate total cost values for allocating available frequency slots over each of the identified potential paths for the new circuit based on the costs determined for the frequency slots for each optical link along the potential paths; 
 select one of the identified potential paths and one or more of the available frequency slots for the new circuit based on the calculated total cost values; and 
 communicate routing and spectrum allocation instructions based on the selected path and the selected one or more frequency slots to a plurality of nodes in the network to implement the new circuit. 
 
     
     
       17. The system of  claim 16 , wherein selecting one or more of the available frequency slots for the new circuit comprises selecting a plurality of adjacent frequency slots. 
     
     
       18. The system of  claim 16 , wherein the processor is configured to assign a higher cost to frequency slots that are available for longer circuits and a lower cost to frequency slots that are only available for shorter circuits. 
     
     
       19. The system of  claim 16 , wherein the cost of allocating one frequency slot over a given optical link to a new circuit differs from the cost of allocating a different frequency slot over the given optical to the new circuit based on the locations of the frequency slots in the electromagnetic spectrum. 
     
     
       20. The system of  claim 16 , wherein the processor is configured to, after selecting one of the identified potential paths and one or more of the available frequency slots for the new circuit based on the calculated total cost values, calculate updated costs for frequency slots over a plurality of optical links in the optical mesh network based on the selection.